The present invention relates to an indexing cover for knock-out punches.
Knock-out punches of the type disclosed in U.S. Pat. No. 2,221,904 issued Nov. 19, 1940 to J. H. Abramson et al are in common usage. Such punches are frequently used by electricians to form openings or enlarging existing openings in circuit cabinets, panels, chassis or junction boxes. When used for enlarging existing openings, the knock-out punch cannot be easily centered in or aligned with respect to the opening. Although some existing metal punches include scribe marks on the cylindrical side wall of the upper die member, such marks formed in the steel body are not readily visible under ambient light conditions.
Also on construction sites, the electrician is frequently confronted with relatively low, ambient light conditions or areas of limited access making it even more difficult to align a knock-out punch for proper location of an aperture formed thereby.